Bug 504221 part 5. Switch from GetFirstChild to GetChildList (returning an nsFrameList). For now, keep a GetFirstChild shim so callers don't have to be updated. r=fantasai, r+sr=roc

layout/forms/nsComboboxControlFrame.cpp

@@ -1230,13 +1230,13 @@ nsComboboxControlFrame::Destroy()
 }
 
 
-nsIFrame*
-nsComboboxControlFrame::GetFirstChild(nsIAtom* aListName) const
+nsFrameList
+nsComboboxControlFrame::GetChildList(nsIAtom* aListName) const
 {
   if (nsGkAtoms::selectPopupList == aListName) {
-    return mPopupFrames.FirstChild();
+    return mPopupFrames;
   }
-  return nsBlockFrame::GetFirstChild(aListName);
+  return nsBlockFrame::GetChildList(aListName);
 }
 
 NS_IMETHODIMP

layout/forms/nsComboboxControlFrame.h

@@ -141,7 +141,7 @@ public:
   NS_IMETHOD GetFrameName(nsAString& aResult) const;
 #endif
   virtual void Destroy();
-  virtual nsIFrame* GetFirstChild(nsIAtom* aListName) const;
+  virtual nsFrameList GetChildList(nsIAtom* aListName) const;
   NS_IMETHOD SetInitialChildList(nsIAtom*        aListName,
                                  nsIFrame*       aChildList);
   virtual nsIAtom* GetAdditionalChildListName(PRInt32 aIndex) const;

layout/generic/nsAbsoluteContainingBlock.h

@@ -84,7 +84,7 @@ public:
   nsIAtom* GetChildListName() const { return mChildListName; }
 #endif
 
-  nsIFrame* GetFirstChild() const { return mAbsoluteFrames.FirstChild(); }
+  const nsFrameList& GetChildList() const { return mAbsoluteFrames; }
 
   nsresult SetInitialChildList(nsIFrame*       aDelegatingFrame,
                                nsIAtom*        aListName,

layout/generic/nsBlockFrame.cpp

@@ -513,13 +513,16 @@ nsBlockFrame::GetBaseline() const
 /////////////////////////////////////////////////////////////////////////////
 // Child frame enumeration
 
-nsIFrame*
-nsBlockFrame::GetFirstChild(nsIAtom* aListName) const
+nsFrameList
+nsBlockFrame::GetChildList(nsIAtom* aListName) const
 {
   if (nsGkAtoms::absoluteList == aListName) {
-    return mAbsoluteContainer.GetFirstChild();
+    return mAbsoluteContainer.GetChildList();
   }
   else if (nsnull == aListName) {
+    // XXXbz once we start using mFrames, or some other sane storage for our
+    // in-flow kids, we could switch GetChildList to returning a |const
+    // nsFrameList&|.
     return (mLines.empty()) ? nsnull : mLines.front()->mFirstChild;
   }
   else if (aListName == nsGkAtoms::overflowList) {
@@ -527,15 +530,15 @@ nsBlockFrame::GetFirstChild(nsIAtom* aListName) const
     return overflowLines ? overflowLines->front()->mFirstChild : nsnull;
   }
   else if (aListName == nsGkAtoms::overflowOutOfFlowList) {
-    return GetOverflowOutOfFlows().FirstChild();
+    return GetOverflowOutOfFlows();
   }
   else if (aListName == nsGkAtoms::floatList) {
-    return mFloats.FirstChild();
+    return mFloats;
   }
   else if (aListName == nsGkAtoms::bulletList) {
     return (HaveOutsideBullet()) ? mBullet : nsnull;
   }
-  return nsContainerFrame::GetFirstChild(aListName);;
+  return nsContainerFrame::GetChildList(aListName);
 }
 
 nsIFrame*
@@ -6164,8 +6167,9 @@ nsBlockFrame::BuildDisplayList(nsDisplayListBuilder*   aBuilder,
     DisplayOverflowContainers(aBuilder, aDirtyRect, aLists);
   }
 
-  aBuilder->MarkFramesForDisplayList(this, mFloats.FirstChild(), aDirtyRect);
-  aBuilder->MarkFramesForDisplayList(this, mAbsoluteContainer.GetFirstChild(), aDirtyRect);
+  aBuilder->MarkFramesForDisplayList(this, mFloats, aDirtyRect);
+  aBuilder->MarkFramesForDisplayList(this, mAbsoluteContainer.GetChildList(),
+                                     aDirtyRect);
 
   // Don't use the line cursor if we might have a descendant placeholder ...
   // it might skip lines that contain placeholders but don't themselves

layout/generic/nsBlockFrame.h

@@ -176,7 +176,7 @@ public:
                            nsIFrame*       aFrameList);
   NS_IMETHOD  RemoveFrame(nsIAtom*        aListName,
                           nsIFrame*       aOldFrame);
-  virtual nsIFrame* GetFirstChild(nsIAtom* aListName) const;
+  virtual nsFrameList GetChildList(nsIAtom* aListName) const;
   virtual nsIFrame* GetLastChild(nsIAtom* aListName) const;
   virtual nscoord GetBaseline() const;
   virtual nsIAtom* GetAdditionalChildListName(PRInt32 aIndex) const;

layout/generic/nsContainerFrame.cpp

@@ -311,28 +311,34 @@ nsContainerFrame::Destroy()
 /////////////////////////////////////////////////////////////////////////////
 // Child frame enumeration
 
-nsIFrame*
-nsContainerFrame::GetFirstChild(nsIAtom* aListName) const
+nsFrameList
+nsContainerFrame::GetChildList(nsIAtom* aListName) const
 {
   // We only know about the unnamed principal child list and the overflow
-  // list
+  // lists
   if (nsnull == aListName) {
-    return mFrames.FirstChild();
-  } else if (nsGkAtoms::overflowList == aListName) {
+    return mFrames;
+  }
+
+  if (nsGkAtoms::overflowList == aListName) {
     nsFrameList* frameList = GetOverflowFrames();
-    return frameList ? frameList->FirstChild() : nsnull;
-  } else if (nsGkAtoms::overflowContainersList == aListName) {
+    return frameList ? *frameList : nsFrameList::EmptyList();
+  }
+
+  if (nsGkAtoms::overflowContainersList == aListName) {
     nsFrameList* list = GetPropTableFrames(PresContext(),
                           nsGkAtoms::overflowContainersProperty);
-    return (list) ? list->FirstChild() : nsnull;
-  } else if (nsGkAtoms::excessOverflowContainersList == aListName) {
+    return list ? *list : nsFrameList::EmptyList();
+  }
+
+  if (nsGkAtoms::excessOverflowContainersList == aListName) {
     nsFrameList* list = GetPropTableFrames(PresContext(),
                           nsGkAtoms::excessOverflowContainersProperty);
-    return (list) ? list->FirstChild() : nsnull;
+    return list ? *list : nsFrameList::EmptyList();
 
-  } else {
-    return nsnull;
   }
+
+  return nsFrameList::EmptyList();
 }
 
 #define NS_CONTAINER_FRAME_OVERFLOW_LIST_INDEX                   0

layout/generic/nsContainerFrame.h

@@ -87,7 +87,7 @@ public:
   NS_IMETHOD RemoveFrame(nsIAtom*  aListName,
                          nsIFrame* aOldFrame);
 
-  virtual nsIFrame* GetFirstChild(nsIAtom* aListName) const;
+  virtual nsFrameList GetChildList(nsIAtom* aListName) const;
   virtual nsIAtom* GetAdditionalChildListName(PRInt32 aIndex) const;
   virtual void Destroy();
   virtual void ChildIsDirty(nsIFrame* aChild);

layout/generic/nsFrame.cpp

@@ -759,10 +759,10 @@ nsFrame::GetAdditionalChildListName(PRInt32 aIndex) const
   return nsnull;
 }
 
-nsIFrame*
-nsFrame::GetFirstChild(nsIAtom* aListName) const
+nsFrameList
+nsFrame::GetChildList(nsIAtom* aListName) const
 {
-  return nsnull;
+  return nsFrameList::EmptyList();
 }
 
 static nsIFrame*

layout/generic/nsFrame.h

@@ -179,7 +179,7 @@ public:
   NS_IMETHOD  SetParent(const nsIFrame* aParent);
   virtual nscoord GetBaseline() const;
   virtual nsIAtom* GetAdditionalChildListName(PRInt32 aIndex) const;
-  virtual nsIFrame* GetFirstChild(nsIAtom* aListName) const;
+  virtual nsFrameList GetChildList(nsIAtom* aListName) const;
   NS_IMETHOD  HandleEvent(nsPresContext* aPresContext, 
                           nsGUIEvent*     aEvent,
                           nsEventStatus*  aEventStatus);

layout/generic/nsHTMLFrame.cpp

@@ -107,7 +107,7 @@ public:
                          nsIFrame*       aOldFrame);
 
   virtual nsIAtom* GetAdditionalChildListName(PRInt32 aIndex) const;
-  virtual nsIFrame* GetFirstChild(nsIAtom* aListName) const;
+  virtual nsFrameList GetChildList(nsIAtom* aListName) const;
 
   virtual nscoord GetMinWidth(nsIRenderingContext *aRenderingContext);
   virtual nscoord GetPrefWidth(nsIRenderingContext *aRenderingContext);
@@ -383,13 +383,13 @@ CanvasFrame::GetAdditionalChildListName(PRInt32 aIndex) const
   return nsHTMLContainerFrame::GetAdditionalChildListName(aIndex);
 }
 
-nsIFrame*
-CanvasFrame::GetFirstChild(nsIAtom* aListName) const
+nsFrameList
+CanvasFrame::GetChildList(nsIAtom* aListName) const
 {
   if (nsGkAtoms::absoluteList == aListName)
-    return mAbsoluteContainer.GetFirstChild();
+    return mAbsoluteContainer.GetChildList();
 
-  return nsHTMLContainerFrame::GetFirstChild(aListName);
+  return nsHTMLContainerFrame::GetChildList(aListName);
 }
 
 nsRect CanvasFrame::CanvasArea() const
@@ -477,7 +477,8 @@ CanvasFrame::BuildDisplayList(nsDisplayListBuilder*   aBuilder,
     DisplayOverflowContainers(aBuilder, aDirtyRect, aLists);
   }
 
-  aBuilder->MarkFramesForDisplayList(this, mAbsoluteContainer.GetFirstChild(), aDirtyRect);
+  aBuilder->MarkFramesForDisplayList(this, mAbsoluteContainer.GetChildList(),
+                                     aDirtyRect);
   
   // Force a background to be shown. We may have a background propagated to us,
   // in which case GetStyleBackground wouldn't have the right background

layout/generic/nsIFrame.h

@@ -848,14 +848,23 @@ public:
   virtual nsIAtom* GetAdditionalChildListName(PRInt32 aIndex) const = 0;
 
   /**
-   * Get the first child frame from the specified child list.
+   * Get the specified child list.
    *
    * @param   aListName the name of the child list. A NULL pointer for the atom
    *            name means the unnamed principal child list
-   * @return  the child frame, or NULL if there is no such child
+   * @return  the child list.  If this is an unknown list name, an empty list
+   *            will be returned.
    * @see     #GetAdditionalListName()
    */
-  virtual nsIFrame* GetFirstChild(nsIAtom* aListName) const = 0;
+  // XXXbz if all our frame storage were actually backed by nsFrameList, we
+  // could make this return a const reference...  nsBlockFrame is the only real
+  // culprit here.  Make sure to assign the return value of this function into
+  // a |const nsFrameList&|, not an nsFrameList.
+  virtual nsFrameList GetChildList(nsIAtom* aListName) const = 0;
+  // XXXbz this method should go away
+  nsIFrame* GetFirstChild(nsIAtom* aListName) const {
+    return GetChildList(aListName).FirstChild();
+  }
 
   /**
    * Get the last child frame from the specified child list.

layout/generic/nsInlineFrame.cpp

@@ -1148,7 +1148,8 @@ nsPositionedInlineFrame::BuildDisplayList(nsDisplayListBuilder*   aBuilder,
                                           const nsRect&           aDirtyRect,
                                           const nsDisplayListSet& aLists)
 {
-  aBuilder->MarkFramesForDisplayList(this, mAbsoluteContainer.GetFirstChild(), aDirtyRect);
+  aBuilder->MarkFramesForDisplayList(this, mAbsoluteContainer.GetChildList(),
+				     aDirtyRect);
   return nsHTMLContainerFrame::BuildDisplayList(aBuilder, aDirtyRect, aLists);
 }
 
@@ -1161,13 +1162,13 @@ nsPositionedInlineFrame::GetAdditionalChildListName(PRInt32 aIndex) const
   return nsnull;
 }
 
-nsIFrame*
-nsPositionedInlineFrame::GetFirstChild(nsIAtom* aListName) const
+nsFrameList
+nsPositionedInlineFrame::GetChildList(nsIAtom* aListName) const
 {
   if (nsGkAtoms::absoluteList == aListName)
-    return mAbsoluteContainer.GetFirstChild();
+    return mAbsoluteContainer.GetChildList();
 
-  return nsInlineFrame::GetFirstChild(aListName);
+  return nsInlineFrame::GetChildList(aListName);
 }
 
 nsIAtom*

layout/generic/nsInlineFrame.h

@@ -272,7 +272,7 @@ public:
 
   virtual nsIAtom* GetAdditionalChildListName(PRInt32 aIndex) const;
 
-  virtual nsIFrame* GetFirstChild(nsIAtom* aListName) const;
+  virtual nsFrameList GetChildList(nsIAtom* aListName) const;
 
   NS_IMETHOD Reflow(nsPresContext*          aPresContext,
                     nsHTMLReflowMetrics&     aDesiredSize,

layout/generic/nsViewportFrame.cpp

@@ -97,7 +97,8 @@ ViewportFrame::BuildDisplayList(nsDisplayListBuilder*   aBuilder,
   // mark our visible out-of-flow frames (i.e., the fixed position frames) so
   // that display list construction is guaranteed to recurse into their
   // ancestors.
-  aBuilder->MarkFramesForDisplayList(this, mFixedContainer.GetFirstChild(), aDirtyRect);
+  aBuilder->MarkFramesForDisplayList(this, mFixedContainer.GetChildList(),
+                                     aDirtyRect);
 
   nsIFrame* kid = mFrames.FirstChild();
   if (!kid)
@@ -120,7 +121,7 @@ ViewportFrame::AppendFrames(nsIAtom*        aListName,
   }
   else {
     NS_ASSERTION(!aListName, "unexpected child list");
-    NS_ASSERTION(!GetFirstChild(nsnull), "Shouldn't have any kids!");
+    NS_ASSERTION(GetChildList(nsnull).IsEmpty(), "Shouldn't have any kids!");
     rv = nsContainerFrame::AppendFrames(aListName, aFrameList);
   }
 
@@ -139,7 +140,7 @@ ViewportFrame::InsertFrames(nsIAtom*        aListName,
   }
   else {
     NS_ASSERTION(!aListName, "unexpected child list");
-    NS_ASSERTION(!GetFirstChild(nsnull), "Shouldn't have any kids!");
+    NS_ASSERTION(GetChildList(nsnull).IsEmpty(), "Shouldn't have any kids!");
     rv = nsContainerFrame::InsertFrames(aListName, aPrevFrame, aFrameList);
   }
 
@@ -175,13 +176,13 @@ ViewportFrame::GetAdditionalChildListName(PRInt32 aIndex) const
   return nsnull;
 }
 
-nsIFrame*
-ViewportFrame::GetFirstChild(nsIAtom* aListName) const
+nsFrameList
+ViewportFrame::GetChildList(nsIAtom* aListName) const
 {
   if (nsGkAtoms::fixedList == aListName)
-    return mFixedContainer.GetFirstChild();
+    return mFixedContainer.GetChildList();
 
-  return nsContainerFrame::GetFirstChild(aListName);
+  return nsContainerFrame::GetChildList(aListName);
 }
 
 /* virtual */ nscoord
@@ -304,8 +305,8 @@ ViewportFrame::Reflow(nsPresContext*           aPresContext,
   nsPoint offset = AdjustReflowStateForScrollbars(&reflowState);
   
 #ifdef DEBUG
-  nsIFrame* f = mFixedContainer.GetFirstChild();
-  NS_ASSERTION(!f || (offset.x == 0 && offset.y == 0),
+  NS_ASSERTION(mFixedContainer.GetChildList().IsEmpty() ||
+               (offset.x == 0 && offset.y == 0),
                "We don't handle correct positioning of fixed frames with "
                "scrollbars in odd positions");
 #endif

layout/generic/nsViewportFrame.h

@@ -86,7 +86,7 @@ public:
 
   virtual nsIAtom* GetAdditionalChildListName(PRInt32 aIndex) const;
 
-  virtual nsIFrame* GetFirstChild(nsIAtom* aListName) const;
+  virtual nsFrameList GetChildList(nsIAtom* aListName) const;
 
   NS_IMETHOD BuildDisplayList(nsDisplayListBuilder*   aBuilder,
                               const nsRect&           aDirtyRect,

layout/tables/nsTableFrame.cpp

@@ -1214,14 +1214,14 @@ nsTableFrame::InsertRowGroups(nsIFrame* aFirstRowGroupFrame,
 /////////////////////////////////////////////////////////////////////////////
 // Child frame enumeration
 
-nsIFrame*
-nsTableFrame::GetFirstChild(nsIAtom* aListName) const
+nsFrameList
+nsTableFrame::GetChildList(nsIAtom* aListName) const
 {
   if (aListName == nsGkAtoms::colGroupList) {
-    return mColGroups.FirstChild();
+    return mColGroups;
   }
 
-  return nsHTMLContainerFrame::GetFirstChild(aListName);
+  return nsHTMLContainerFrame::GetChildList(aListName);
 }
 
 nsIAtom*

layout/tables/nsTableFrame.h

@@ -260,10 +260,7 @@ public:
   NS_IMETHOD SetInitialChildList(nsIAtom*        aListName,
                                  nsIFrame*       aChildList);
 
-  /** return the first child belonging to the list aListName. 
-    * @see nsIFrame::GetFirstChild
-    */
-  virtual nsIFrame* GetFirstChild(nsIAtom* aListName) const;
+  virtual nsFrameList GetChildList(nsIAtom* aListName) const;
 
   /** @see nsIFrame::GetAdditionalChildListName */
   virtual nsIAtom* GetAdditionalChildListName(PRInt32 aIndex) const;

layout/tables/nsTableOuterFrame.cpp

@@ -215,16 +215,16 @@ nsTableOuterFrame::Destroy()
   nsHTMLContainerFrame::Destroy();
 }
 
-nsIFrame*
-nsTableOuterFrame::GetFirstChild(nsIAtom* aListName) const
+nsFrameList
+nsTableOuterFrame::GetChildList(nsIAtom* aListName) const
 {
   if (nsGkAtoms::captionList == aListName) {
-    return mCaptionFrames.FirstChild();
+    return mCaptionFrames;
   }
   if (!aListName) {
-    return mFrames.FirstChild();
+    return mFrames;
   }
-  return nsnull;
+  return nsFrameList::EmptyList();
 }
 
 nsIAtom*

layout/tables/nsTableOuterFrame.h

@@ -105,7 +105,7 @@ public:
   NS_IMETHOD SetInitialChildList(nsIAtom*        aListName,
                                  nsIFrame*       aChildList);
  
-  virtual nsIFrame* GetFirstChild(nsIAtom* aListName) const;
+  virtual nsFrameList GetChildList(nsIAtom* aListName) const;
 
   virtual nsIAtom* GetAdditionalChildListName(PRInt32 aIndex) const;
 

layout/xul/base/src/nsMenuFrame.cpp

@@ -325,13 +325,13 @@ nsMenuFrame::~nsMenuFrame()
 
 // The following methods are all overridden to ensure that the menupopup frame
 // is placed in the appropriate list.
-nsIFrame*
-nsMenuFrame::GetFirstChild(nsIAtom* aListName) const
+nsFrameList
+nsMenuFrame::GetChildList(nsIAtom* aListName) const
 {
   if (nsGkAtoms::popupList == aListName) {
     return mPopupFrame;
   }
-  return nsBoxFrame::GetFirstChild(aListName);
+  return nsBoxFrame::GetChildList(aListName);
 }
 
 nsIFrame*

layout/xul/base/src/nsMenuFrame.h

@@ -130,7 +130,7 @@ public:
   // The following methods are all overridden so that the menupopup
   // can be stored in a separate list, so that it doesn't impact reflow of the
   // actual menu item at all.
-  virtual nsIFrame* GetFirstChild(nsIAtom* aListName) const;
+  virtual nsFrameList GetChildList(nsIAtom* aListName) const;
   NS_IMETHOD SetInitialChildList(nsIAtom*        aListName,
                                  nsIFrame*       aChildList);
   virtual nsIAtom* GetAdditionalChildListName(PRInt32 aIndex) const;